Loader work machine

ABSTRACT

A loader work machine has a base frame including a cabin; a loader work apparatus attached to the base frame; and two traveling apparatuses supporting the base frame, and including: a track frame connected to the base frame; a drive wheel driving a traveling belt; front and rear idlers arranged in a front-back direction below the drive wheel and supported by the track frame; and one or more track rollers arranged between the front and rear idlers and supported by the track frame, the traveling belt stretched around the drive wheel, idlers, and track rollers. The base frame includes: a lower frame connected to two track frames and interposed between the traveling apparatuses; an upper frame provided with the loader work apparatus; and a slewing apparatus connecting the upper and lower frames. The upper frame connected to the lower at an upper frame bottom surface being above the traveling belts.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a loader work machine.

Description of the Related Art

For example, as illustrated in FIG. 6, a known conventional loader workmachine (track loader) includes: a pair of traveling apparatuses 201; abase frame 202 that is supported by the traveling apparatuses 201 andincludes a cabin 202A and an engine room 202B in an upper part of thebase frame 202; booms 203 that are each attached to the base frame 202via a lift link 204 and have leading ends to which a bucket 206 isprovided; and boom cylinders 205 that respectively move the booms 203up/down with respect to the base frame 202.

Crawler traveling apparatuses each having a substantially triangularrice ball shape are frequently used for such a loader work machine inorder to enhance the traveling performance. Moreover, the center ofgravity of such a loader work machine is lowered in order to enhance thetraveling performance. Hence, the base frame is sandwiched between thepair of traveling apparatuses,

Such a loader work machine as described above can insert a work toolsuch as the bucket located in a front part of the loader work machine,into a piled-up object such as piled-up earth, sand, and rubble or intothe ground, using a thrust generated by forward movement of thetraveling apparatuses, and thus can pick up a transportation targetobject such as earth and sand to be transported. Then, the loader workmachine can move and unload the transportation target object to adesired unloading place, or can load the transportation target objectonto a transporting vehicle such as a dump truck (see, for example, U.S.Pat. No. 8,342,789).

Because the loader work machine described in U.S. Pat. No. 8,342,789 hasthe above-mentioned configuration, the work tool is fixed to thedirection in which the base frame faces. Hence, in the case where thetransportation target object being transported by the work tool isunloaded to a desired place, it is necessary to change the direction ofthe loader work machine itself such that the front side of the loaderwork machine faces the place, while the loader work machine is caused totravel. Moreover, such a work process is normally repeated several timesin many cases.

As a result, the operating time of the traveling apparatuses becomeslonger, so that the product lifetime of the traveling apparatusesbecomes shorter. Accordingly, there is a problem that the running costof the loader work machine becomes higher.

The present invention, which has been made in view of theabove-mentioned problem, has an object to provide a loader work machinethat can improve the product lifetime of traveling apparatuses tothereby reduce running cost.

SUMMARY OF THE INVENTION

In order to achieve the above-mentioned object, a loader work machinereflecting one aspect of the present invention includes a base frameincluding a cabin; a loader work apparatus attached to the base frame;and a pair of traveling apparatuses that support the base frame. Thetraveling apparatuses each include: a track frame connected to the baseframe; a drive wheel that rotationally drives a traveling belt; a frontidler and a rear idler that are arranged in a front-back direction belowthe drive wheel and are rotatably supported by the track frame; and oneor more track rollers that are arranged between the front idler and therear idler and are rotatably supported by the track frame, the travelingbelt being stretched around the drive wheel, the front idler, the rearidler, and the track rollers. The base frame includes: a lower framethat is connected to a pair of the track frames and is interposedbetween the pair of traveling apparatuses; an upper frame that isprovided with the loader work apparatus and is arranged above the lowerframe; and a slewing apparatus that slewably connects the upper frame tothe lower frame. The upper frame is connected to the lower frame at aposition at which a bottom surface of the upper frame is above thetraveling belts.

More preferably, the slewing apparatus includes a slewing bearing, andis capable of slewing the upper frame 360 degrees with respect to thelower frame.

More preferably, the loader work apparatus includes: a pair of right andleft booms supported by the base frame; a work tool provided to leadingends of the pair of booms; and a swinging apparatus capable of swingingthe pair of booms in a top-bottom direction, and the loader workapparatus further includes a moving apparatus capable of moving the pairof booms forward.

More preferably, the moving apparatus includes: movement cylinders thatare supported by the base frame and are each made of a hydrauliccylinder; and link members that are turnably supported by the base frameand each have one end connected to each of the movement cylinders andanother end connected to each of the pair of booms, the swingingapparatus includes boom cylinders that are supported by the base frameand are each made of a hydraulic cylinder, and the pair of booms aremade movable forward by respectively driving the link members by themovement cylinders in a state where the pair of booms are respectivelysupported by the boom cylinders.

According to the present invention, it is possible to provide a loaderwork machine that can improve the product lifetime of travelingapparatuses to thereby reduce running cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a track loader according to the presentembodiment;

FIG. 2 is an enlarged cross-sectional view taken along A-A in FIG. 1;

FIG. 3 is a side view illustrating the state where the track loaderaccording to the present embodiment is inclined;

FIG. 4A is a diagram for describing an operation of unloading atransportation target object by a conventional track loader;

FIG. 4B is a diagram for describing an operation of unloading atransportation target object by the track loader according to thepresent embodiment;

FIG. 5 is a partial enlarged view illustrating a modified example of aloader work apparatus; and

FIG. 6 is a side view illustrating an example conventional track loader.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, a track loader as a loader work machine according to anembodiment of the present invention is described with reference to thedrawings. The scope of the present invention is not limited to examplesillustrated in the drawings. Note that, in the following description,elements having the same functions and configurations are denoted by thesame reference signs, and description thereof is omitted.

Before the track loader according to the present embodiment isdescribed, an example conventional track loader is first described withreference to FIG. 6. FIG.. 6 is a side view illustrating the exampleconventional track loader. In the following description, the top-bottom,the right-left, and the front-back respectively mean the top-bottom, theright-left, and the front-back based on the direction of eyes of anoperator who gets in and drives the track loader.

As illustrated in FIG. 6, a conventional track loader 200 includes, forexample, traveling apparatuses 201, a base frame 202, booms 203, liftlinks 204, boom cylinders 205, and a bucket 206.

One traveling apparatus 201 is attached on each of the right and leftsides of the base frame 202, and the two traveling apparatuses 201support the base frame 202. Each traveling apparatus 201 includes, forexample, a track frame 201 a, a sprocket 201 b, a front idler 201 c, arear idler 201 d, four track rollers 201 e, and a rubber track 201 f.

The track frame 201 a is a member having an inverted U shape incross-section extending in the front-back direction, and is attached tothe base frame 202. The track frame 201 a rotatably supports the frontidler 201 c, the rear idler 201 d, and the track rollers 201 e. Thesprocket 201 b is arranged above the track frame 201 a, and the sprocket201 b is rotatably supported by the track frame 201 a via a supportmember 201g.

The sprocket 201 b is formed in a discoid shape, and is attached to aslightly back part from the center of the base frame 202. Countlessteeth are formed on the outer circumference of the sprocket 201 b. Thecenter of the sprocket 201 h is borne by a drive shaft 201 h thattransmits driving force from an engine, whereby the sprocket 201 h canrotate about the drive shaft 201 h in accordance with the driving forcefrom the engine. The sprocket 201 b rotates while the countless teethformed on the outer circumference thereof are meshed with sprocket holesthat are formed at predetermined intervals on the inner circumference ofthe rubber track 201 f, whereby the sprocket 201 b can rotationallydrive the rubber track 201 f. That is, the sprocket 201 b functions as adrive wheel that rotationally drives the rubber track 201 f,

The front idler 201 c is rotatably supported by a leading end portion ofthe track frame 201 a via a tensioner (not illustrated). The tensionergives pressing force to the front idler 201 c, and adjusts the tensionof the rubber track 201 f to a constant value. The rear idler 201 d isrotatably supported by a back end portion of the track frame 201 a. Thefour track rollers 201 e are arranged at regular intervals in thefront-back direction between the front idler 201 c and the rear idler201 d, and are rotatably supported by the track frame 201 a. The frontidler 201 c, the rear idler 201 d, and the track rollers 201 e functionas idler wheels. Note that, although the four track rollers 201 e areprovided in the present embodiment, the number of the track rollers 201e is not limited thereto, and can be set to an appropriate number.Moreover, the track rollers 201 e may not be Provided.

The rubber track 201 f is made of a plastic material such as rubber, andis a belt member formed in an endless belt shape. As described above,the sprocket holes are formed at predetermined intervals in the centerof the inner circumference of the rubber track 201 f, and the teeth ofthe sprocket 201 b can be inserted into and removed from the sprocketholes. The intervals of the sprocket holes are coincident with pitchesof the teeth of the sprocket 201 b. The outer circumference of therubber track 201 f is a tread, and patterns for increasing driving forceand braking force are formed on the outer circumference thereof. Therubber track 201 f thus formed is rotatably attached by the sprocket 201b, the front idler 201 c, the rear idler 201 d, and the track rollers201 e.

Because each traveling apparatus 201 is configured as described above,the traveling apparatus 201 has a substantially triangular rice ballshape protruding upward. As a result, the sprocket 201 b is at aposition away from a ground contact surface, and hence a foreignsubstance such as a pebble can be prevented from being caught in thesprocket 201 b to cause a trouble at the time of traveling,

The base frame 202 includes a cabin 202A and an engine room 202B in anupper part of the base frame 202. The cabin 202A. is surrounded by, forexample, a front window, an entrance/exit door, side windows, and a rearwindow, and is provided with a driver's seat, a steering handle, atransmission, and the like inside thereof. The operator can get in thecabin 202A by opening/closing the entrance/exit, door. The engine room202E houses, for example, the engine for driving the track loader 200 totravel.

The booms 203 are arranged in a pair on the right and left sides of thebase frame 202 so as to sandwich the base frame 202, and each have aback end part that is attached to the base frame 202 via the lift link204, whereby the booms 203 are swingable in the top-bottom direction.The bucket 206 as a work tool is attached to the leading ends of thepair of booms 203. The bucket 206 is formed in a concave shape so as tobe capable of housing earth, sand, and rubble. The bucket 206 is madeturnable by, for example, bucket cylinders (not illustrated) in thetop-bottom direction in a range indicated by an arrow M2, and can unload(dump) a transportation target object such as earth, sand, and rubblehoused in the bucket 206. Each lift link 204 has: a base end partturnably supported by a substantially central part of the base frame202; and a leading end part turnably supported by a back end part ofeach boom 203. Each boom cylinder 205 is made of a hydraulic cylinder,and is capable of moving a rod forward/backward using a hydraulicpressure. The boom cylinders 205 are provided in a pair on the right andleft sides of the base frame 202 so as to sandwich the base frame 202.The pair of boom cylinders 205 each include: a cylinder part having abase part turnably attached to a side surface of the base frame 202; andthe rod having a leading end part turnably attached to each boom 203.The attachment position of the leading end part of the rod of each boomcylinder 205 is on the leading end side from the attachment position ofeach lift link 204 in each boom 203.

In the track loader 200 configured as described above, when each boomcylinder 205 is driven to be elongated, each lift link 204 turns aboutthe base end part thereof supported by the base frame 202 as a turnsupporting axis. Consequently, the leading end part of each lift link204 (that is, the back end part of each boom 203) moves along atrajectory indicated by an alternate long and short dash line L. Then,each boom 203 can be swung upward along with the elongation of each boomcylinder 205 to be moved from a position indicated by X2 to a positionindicated by Y2. In this way, the booms 203, the lift links 204, theboom cylinders 205, and the bucket 206 constitute a loader workapparatus.

While being moved forward by the traveling apparatuses 201, the trackloader 200 configured as described above can insert the bucket 206 intoa piled-up object such as piled-up earth, sand, and rubble or into theground, using a thrust generated by the forward movement, and thus canpick up a transportation target object such as earth and sand to betransported. Then, the track loader 200 can travel with thetransportation target object being housed in the bucket 206, can moveand unload the transportation target object to a desired unloadingplace, or can load the transportation target object onto a transportingvehicle such as a dump truck. Moreover, the track loader 200 can performground leveling work by moving backward while bringing the bottomsurface of the bucket 206 into contact with a ground surface to beleveled.

Because the track loader 200 is configured as described above, the trackloader 200 has a low center of gravity, and is excellent in travelingstability. Moreover, because the track loader 200 includes the travelingapparatuses 201 configured as described above, the track loader 200 isexcellent in traveling performance. In the track loader 200 describedabove, however, the base frame 202 is arranged so as to be sandwichedbetween the pair of traveling apparatuses 201, and hence, in the case ofchanging the direction of the bucket 206, it is necessary to drive thetraveling apparatuses 201 and change the direction of the track loader200 itself, so that wasting of the traveling apparatuses 201 is large.

In view of the above-mentioned problem, the track loader according tothe present embodiment can reduce such wasting of the travelingapparatuses in the following manner,

Next, the track loader according to the present embodiment is describedwith reference to FIG. 1 to FIG. 3, FIG. 1 is a side view of a trackloader 100 according to the present embodiment. FIG. 2 is across-sectional view that is taken in an arrow direction along a lineA-A in FIG, 1, and is an enlarged cross-sectional view of a portion of alower frame 103. FIG. 3 is a side view illustrating the state where thetrack loader 100 according to the present embodiment is inclinedbackward.

As illustrated in FIG. 1, the track loader 100 according to the presentembodiment includes, for example, traveling apparatuses 101 and a baseframe 102. The traveling apparatuses 101 have a configuration similar tothat of the traveling apparatuses 201 in the conventional track loader200 described with reference to FIG. 6. Accordingly, detaileddescription of the traveling apparatuses 101 is omitted.

The base frame 102 includes the lower frame 103 and an upper frame 104.The upper frame 104 is arranged above the lower frame 103, and isconnected to the lower frame 103 via a slewing bearing 105. The upperframe 104 can be stewed by driving the slewing bearing 105.

As illustrated in FIG. 1 and FIG. 2, the lower frame 103 includes a linkframe 103A, a support plate 103B, and a connection part 103C. The linkframe 103A has both ends inclined downward, and is bent in a concaveshape. Both the ends of the link frame 103A are respectively connectedto track frames 101a of the traveling apparatuses 101. As illustrated inFIG. 1, the link frame 103A extends to a position at which the linkframe 103A protrudes more forward than the leading ends of the travelingapparatuses 101. The connection part 103C is provided in a back centerpart of the link frame 103A, and the support plate 103B is connected tothe back center part thereof via the connection part 103C.

The slewing bearing 105 is attached to the upper surface of the supportplate 103B. More specifically, the slewing bearing 105 is a conventionalslewing bearing including, for example, an outer ring 105 a, an innerring 105 b, a pinion gear (not illustrated) that is meshed with a gearformed on the inner circumference of the inner ring, and a hydraulicswing motor (not illustrated) that rotates the pinion gear. Moreover, aswivel joint (not illustrated) is arranged in the center of the slewingbearing 105. The swing motor is connected to the swivel joint by ahydraulic hose, and operating oil is supplied to the swing motor via theswivel joint. The outer ring 105 a and the swing motor are attached tothe upper frame 104, and the inner ring 105 b is attached to the supportplate 103B. Accordingly, when the pinion gear is rotated by driving theswing motor, the outer ring 105 a attached to the upper frame 104 slideson the inner ring 105 b in accordance with the rotational movement ofthe pinion gear along the inner circumference of the inner ring 105 b,and the upper frame 104 slews about an axis R. (that is, the center ofrotation of the slewing bearing 105) as an axis of rotation. With thisstructure, the upper frame 104 can slew 360 degrees can do a fullcircle). Note that the slewable angle of the upper frame 104 may not beset to 360 degrees, and may be restricted to a given angle range (forexample, 180 degrees). Moreover, although the slewing bearing 105 isused as means for stewing the upper frame 104, another apparatus may beadopted as long as the apparatus can slew the upper frame 104. Aconceivable example of the other apparatus is an apparatus in which theupper frame 104 is connected to the axis of rotation and the upper frame104 is slewed by rotations of the axis of rotation.

Here, the upper frame 104 is connected to the lower frame 103 via thestewing bearing 105, at a position at which the bottom surface of theupper frame 104 is above rubber tracks of the traveling apparatuses 101.In the present embodiment, for example, as illustrated in FIG. 2, a gapG is provided between the highest position of the rubber tracks and thebottom surface of the upper frame 104. Note that, in FIG. 1 and FIG. 2,the height from a ground contact surface of the rubber tracks to thehighest position of the rubber tracks is indicated by an arrow H. In thepresent embodiment, the size of the gap G is set to, for example, 47 mm.The size of the gap G can be set as appropriate as long as the rubbertracks do not interfere with the upper frame 104 when the upper frame104 slews. As the size of the gap G is set to be smaller, the totalheight can be suppressed to be smaller. Hence, the center of gravitybecomes lower, and the traveling stability can be more enhanced, whichis preferable.

As illustrated in FIG. 1 to FIG, 3, the connection part 103C is astructure having a predetermined height, and includes a tiltingapparatus 106 and spacers 106 a. In the present embodiment, theconnection part 103C has the predetermined height in order to arrangethe bottom surface of the upper frame 104 above the rubber tracks of thetraveling apparatuses 101. Note that the height of the connection part103C can be set as appropriate,

The spacers 106 a are plate-like members that respectively extenddownward from slightly inner positions from the right and left ends ofthe support plate 103B, and are formed integrally with the support plate103B. A pair of the spacers 106 a each have a back-end lower portionthat is partially cut out in a substantially square shape. Lower endparts of the spacers 106 a abut against the upper surface of the linkframe 103A, whereby the spacers 106 a can stably hold the upper frame104 in a horizontal posture. The pair of spacers 106 a each include arod supporting part 106 a 1 in the vicinity of the leading end on theouter side surface.

The tilting apparatus 106 includes tilt cylinders 106 b, cylindersupporting parts 106 c, and spacer supporting parts 106 d.

Each tilt cylinder 106 b is made of a hydraulic cylinder, and is capableof moving a rod 106 b 2 forward/backward with respect to a cylinder part106 b 1 using a hydraulic pressure. As illustrated in FIG, 2, two tiltcylinders 106 b are provided at a predetermined interval on the rightand left sides, and are respectively arranged on the outer sides of thespacers 106 a. Note that the number of the tilt cylinders 106 b may beone and may be three or more. Each cylinder supporting part 106 c is asupport member that is formed so as to stand from the upper surface in aslightly back part from the center of the link frame 103A, and turnablysupports a base end part of the cylinder part 106 b 1 of each tiltcylinder 106 b. The rod supporting part 106 a 1 of each spacer 106 aturnably supports a leading end part of the rod 106 b 2 of each tiltcylinder 106 b.

The spacer supporting parts 106 d are provided so as to respectivelycorrespond to the pair of spacers 106 a, and are support members thatare formed so as to stand from the upper surface in a back end portionof the link frame 103A. Each spacer supporting part 106 d has asubstantially triangular shape, and has an upper end portion thatturnably supports a back end portion of each spacer 106 a.

When the tilt cylinders 106 h are driven to be elongated, the upperframe 104 turns and tilts about the spacer supporting parts 106 d as aturn supporting axis. As a result, the upper frame 104 can turn up to alimit angle θ with respect to the ground contact surface. In the presentembodiment, the angle θ is set to 10 degrees, but can be set to anappropriate angle.

In the present embodiment, the upper frame 104 is tilted using the tiltcylinders 106 b made of hydraulic cylinders. Alternatively, the upperframe 104 may be tilted using other actuators such as electric motors.

In the upper frame 104, a cabin 104A and an engine room 104B arearranged continuously in the front-back direction. The cabin 104A issurrounded by, for example, a front window, an entrance/exit door, sidewindows, and a rear window, and is provided with a driver's seat 104 f,a steering handle, a transmission, and the like inside thereof.Moreover, in the cabin 104A, a slewing operation and a tilting operationof the upper frame 104 can be performed.

The engine room 104B houses an engine 104 a, a radiator 104 b, an oilcooler 104 c, and an air cleaner 104 d, and a muffler 104 e fordischarging exhaust gas from the engine 104 a is attached upward to theengine room 104B.

The engine 104 a is an internal combustion engine that evaporates afossil fuel such as gasoline, combusts the evaporated fuel while mixingthe evaporated fuel with air taken in via the air cleaner 104 d, andthus can obtain driving force for, for example, causing the track loader100 to travel. The radiator 104 b cools cooling water for cooling theengine 104 a. Note that any of a water-cooled radiator and an air-cooledradiator can be adopted as the radiator 104 b. The oil cooler 104 ccools a lubricant of the engine and the like. Any of a water-cooledcooler and an air-cooled cooler can be adopted as the oil cooler 104 c.

Moreover, a loader work apparatus including booms 107, a bucket 108,bucket cylinders 109, and boom cylinders 112 is attached to the upperframe 104 via support plates 113. The support plates 113 arerespectively provided to the right and left side surfaces of the upperframe 104. Each support plate 113 has a substantially triangular shape,and has an upper end part in which a boom supporting part 113 a isformed; and a front lower part in which a cylinder supporting part 113 bis formed.

The booms 107 are arranged in a pair on the right and left sides of theupper frame 104 so as to sandwich the upper frame 104, and each have abase end part supported by the boom supporting part 113 a of eachsupport plate 113, whereby the booms 107 are attached turnably in thetop-bottom direction. Each boom 107 is formed in a substantially Lshape. A rod supporting part 107 a is provided to a substantially centerlower part of each boom 107. Each boom cylinder 112 is made of ahydraulic cylinder, and is capable of moving a rod 112 bforward/backward with respect to a cylinder part 112 a using a hydraulicpressure. The boom cylinders 112 are provided so as to respectivelycorrespond to a pair of booms 107. A pair of the boom cylinders 112 eachinclude: the cylinder part 112 a having a base part turnably attached tothe cylinder supporting part 113 b of each support plate 113; and therod 112 b having a leading end part turnably attached to the rodsupporting part 107 a of each boom 107. Moreover, a cylinder supportingpart 107 b is provided to the inner side surface of a bent portion ofeach boom 107, and a bucket turning shaft 107 d is provided to a leadingend portion of each boom 107. Moreover, each boom 107 includes a stopper107 c at an appropriate position at which the boom 107 abuts against theleading end of the lower frame 103. The stopper 107 c is made of, forexample, a plastic material such as rubber, and is a member that absorbsa shock when each boom 107 and the lower frame 103 collide against eachother.

The bucket 108 as a work tool is supported by the bucket turning shafts107 d respectively provided to the leading ends of the pair of booms107, and is turnable in the top-bottom direction. The bucket 108 isformed in a concave shape, and is capable of housing earth, sand,rubble, and the like. Each bucket cylinder 109 is made of a hydrauliccylinder, and is capable of moving a rod 109 b forward/backward withrespect to a cylinder part 109 a using a hydraulic pressure. The bucketcylinders 109 are provided so as to respectively correspond to the innersides of the pair of booms 107. A pair of the bucket cylinders 109 eachinclude: the cylinder part 109 a having a base part that is attached tothe cylinder supporting part 107 b of each boom 107 so as to be turnablysupported thereby; and the rod 109 b having a leading end part that isattached to a rod supporting part 108 a so as to be turnably supportedthereby, the rod supporting part 108 a being formed in a base part ofeach bucket 108. As illustrated in FIG. 3, the bucket 108 is madeturnable in the top-bottom direction in a range indicated by an arrow M1by driving the bucket cylinders 109, and can unload (dump) atransportation target object such as earth, sand, and rubble housed inthe bucket 108,

In the track loader 100 configured as described above, when each boomcylinder 112 is driven to be elongated, each boom 107 turns about theboom supporting part 113 a of each support plate 113 as a turnsupporting axis, and can be moved from a position indicated by X1 to aposition indicated by Y1 as illustrated in FIG, 3,

Because the track loader 100 according to the present embodiment isconfigured as described above, the upper frame 104 is slewed by thestewing bearing 105, whereby the direction of the bucket 108 can bechanged without traveling using the traveling apparatuses 101. Hence,according to the present embodiment, the operating time of the travelingapparatuses 101 can be suppressed, and the product lifetime of underbodycomponents such as the traveling apparatuses can be improved.Accordingly, the running cost of the track loader 100 can be reduced.

Moreover, because the track loader 100 according to the presentembodiment includes the connection part 103C having the predeterminedheight, the cabin 104A can be positioned higher. As a result, the pointof view of the operator can be made higher. Hence, the field of view ofthe operator can he widened, and the work safety can be enhanced.

Moreover, because the track loader 100 according to the presentembodiment includes the connection part 103C having the predeterminedheight, the upper frame 104 can be positioned higher. Hence, supportpoints of the booms 107 can also be made higher, and the height of thebucket 108 at the time of upward movement for dumping can be gainedwithout adopting a complicated link mechanism. As a result, the productcost of the track loader 100 is reduced.

Further, in the track loader 100 according to the present embodiment,because the upper frame 104 can be tilted upward, the height of thebucket 108 at the time of upward movement for dumping can be madefurther larger.

Moreover, because the track loader 100 according to the presentembodiment includes the connection part 103C having the predeterminedheight, the minimum ground clearance can be made higher. As a result, abottom part of the track loader 100 can be suppressed from coming intocontact with the ground in a morass, for example. Accordingly, favorablework is possible even in the morass.

Note that, in the present embodiment, in the case where the upper frame104 faces in a direction other than the front side, a tilt restrictingpart that restricts a tilting operation by the tilting apparatus 106 maybe provided. Moreover, in the case where the upper frame 104 isinclined, a slew restricting part that restricts a slewing operation bythe slewing bearing 105 may be provided. In this case, the tiltrestricting part and the slew restricting part may perform mechanicalcontrol, and may perform electronic control.

Moreover, the present embodiment has the function of slewing the upperframe 104 by the slewing bearing 105 and the function of tilting theupper frame 104 by the tilting apparatus 106, but may have aconfiguration without the tilting apparatus 106.

Next, with reference to FIG. 4A and FIG. 4B, an operation of unloading atransportation target object that can be performed by the track loader100 according to the present embodiment is described in comparison withthe conventional track loader 200. FIG. 4A is a diagram for describingthe operation of unloading the transportation target object by theconventional track loader, and FIG. 4E is a diagram for describing theoperation of unloading the transportation target object by the trackloader according to the present embodiment,

As illustrated in FIG. 4A, the conventional track loader 200 performs anoperation of from loading the transportation target object in a loadingplace P to unloading the transportation target object in an unloadingplace Q, according to the following work procedures.

That is, the track loader 200 first moves forward toward the loadingplace 2, and inserts the bucket 206 into a piled-up object piled up inthe loading place P, using a thrust generated by the forward movement.Consequently, the piled-up object is housed as the transportation targetobject into the bucket 206. Subsequently, the track loader 200 movesbackward while being largely steered so as to face the unloading place Qin order to change the direction of the track loader 200. After that,the track loader 200 moves forward toward the unloading place Q, andunloads the transportation target object in the unloading place Q.

In comparison, as illustrated in FIG. 4B, the track loader 100 accordingto the present embodiment can transport the transportation target objectaccording to the following work procedures.

That is, the track loader 100 first moves forward toward the loadingplace P, and inserts the bucket 108 into a piled-up object piled up inthe loading place P, using a thrust generated by the forward movement.Consequently, the piled-up object is housed as the transportation targetobject into the bucket 108. Subsequently, the track loader 100 movesbackward while being slightly steered in order to move the track loader100 to a position close to the unloading place Q. When the track loader100 arrives at the position close to the unloading place Q, the trackloader 100 stops the backward movement, and, in this state, the upperframe 104 is siewed in a counterclockwise direction. Consequently, thebucket 108 is opposed to the unloading place Q, and hence, in thisstate, the track loader 100 can unload the transportation target objectto the unloading place Q.

In this way, according to the present embodiment, because it is notnecessary to change the direction of the track loader itself, the amountof movement of the track loader can be reduced. As a result, the productlifetime of the traveling apparatuses is improved, and the running costof the track loader is reduced.

Next, a modified example of the loader work apparatus applicable to thepresent embodiment is described with reference to FIG. 5. Here, FIG. 5is a partial enlarged view illustrating a modified example of the loaderwork apparatus,

The loader work apparatus illustrated in FIG. 5 is provided to the upperframe 104, and includes, for example, booms 107A, boom cylinders 112A,moving cylinders 114, and moving links 115. Note that, although omittedfrom the illustration in FIG. 5, the bucket 108 described above isattached to the leading ends of the booms 107A. Support plates 113A thatsupport the booms 107A are respectively provided to the right and leftside surfaces of the upper frame 104. Each support plate 113A has asubstantially triangular shape, and has an upper end part in which alink supporting part 116 a is formed. Moreover, the upper frame 104 isprovided with boom cylinder supporting plates 117 that respectivelyturnably support the boom cylinders 112A and moving cylinder supportingplates 115 that respectively turnably support the moving cylinders 114,and the plates 117 and 115 are arranged on the front side from thesupport plates 113A,

Each moving cylinder 114 is made of a hydraulic cylinder, and is capableof moving a rod 114 h forward/backward with respect to a cylinder part114 a using a hydraulic pressure. As described later, the movingcylinders 114 are provided so as to respectively correspond to a pair ofthe booms 107A. A pair of the moving cylinders 114 each include: thecylinder part 114 a having a base part that is attached so as to beturnably supported by a cylinder supporting part 115 a of each movingcylinder supporting plate 115; and the rod 114 h having a leading endpart that is attached so as to be turnably supported by a rod supportingpart 116 b formed in a back end part of each moving link 116.

Each moving link 116 is formed in a substantially inverted V shape, andhas a bent portion swingably supported by the link supporting part 116a. The moving link 116 is supported by the link supporting part 116 a onits slightly back end side from the center. The moving link 116 has aleading end part in which a boom supporting part 116 c is formed, andthe boom supporting part 116 c supports a base end part of each boom107A. With this configuration, the boom 107A is swingable about the boomsupporting part 116 c as a support axis. In this way, in the presentembodiment, the moving cylinders 114 and the moving links 116 constitutea moving apparatus.

The booms 107A are arranged in a pair on the right and left sides of theupper frame 104 so as to sandwich the upper frame 104, and are eachformed in a substantially inverted V shape. A lower part of a bentportion of each boom 107A is provided with a rod supporting part 107Aa.Each boom cylinder 112A is made of a hydraulic cylinder, and is capableof moving a rod 112Ab forward/backward with respect to a cylinder part112Aa using a hydraulic pressure. The boom cylinders 112A are providedso as to respectively correspond to the pair of booms 107A. A pair ofthe boom cylinders 112A each include; the cylinder part 112Aa having abase part turnably attached to a cylinder supporting part 117 a of eachboom cylinder supporting plate 117; and the rod 112Ab having a leadingend part turnably attached to the rod supporting part 107Aa of each boom107A. Note that, although not illustrated, a bucket cylinder forswinging the bucket 108 is also provided in an appropriate place.

In the loader work apparatus configured as described above, when eachboom cylinder 112A is driven to be elongated, each boom 107A swingsabout the base end part of the boom 107A as a support axis, and movesupward together with the bucket 108. Moreover, when each moving cylinder114 is driven to be elongated, each moving link 116 turns about the linksupporting part 116 a as a support axis in a counterclockwise direction.The moving link 116 can move along a trajectory indicated by analternate long and short dash line Y1 between a position indicated bysolid lines and a position indicated by alternate long and two shortdashes lines in FIG. 5. Consequently, the boom 107A supported by theleading end part of the moving link 116 moves along a trajectoryindicated by an alternate long and short dash line Y2 while beingsupported by the boom cylinder 112A, and the boom 107A (and the boomcylinder 112A) move between a position indicated by solid lines and aposition indicated by alternate long and two short dashes lines in FIG.5. With this configuration, the bucket 108 that may be unfavorablylocated backward in the case of moving the booms 107A upward can beshifted forward, and a transportation target object such as earth, sand,and rubble housed in the bucket 108 can be efficiently unloaded(dumped).

As described above, according to the present embodiment, each travelingapparatus 101 includes the track frame 101 a, the sprocket, the frontidler, the rear idler, and the one or more track rollers. The trackframe 101a is connected to the base frame 102. The sprocket rotationallydrives the rubber track. The front idler and the rear idler are arrangedin the front-back direction below the sprocket, and are rotatablysupported by the track frame 101 a. The track rollers are arrangedbetween the front idler and the rear idler, and are rotatably supportedby the track frame 101 a. The base frame 102 includes the lower frame103, the upper frame 104, and the stewing apparatus. The lower frame 103is interposed between the pair of track frames 101 a. The upper frame104 is provided with the loader work apparatus, and is arranged abovethe lower frame 103, The slewing apparatus slewably connects the upperframe 104 to the lower frame 103. The upper frame 104 is connected tothe lower frame 103 at the position at which the bottom surface of theupper frame 104 is above the rubber tracks. As a result, the productlifetime of the traveling apparatuses can be improved, and the runningcost of the loader work machine can be reduced. That is, the upper frameis siewed by the slewing apparatus without changing the direction of theloader work machine, whereby work by the loader work apparatus becomespossible in some cases. Hence, the driving amount of the travelingapparatuses for changing the direction of the loader work machine can bereduced, and the product lifetime of the traveling apparatuses can beimproved.

Moreover, according to the present embodiment, the slewing apparatusincludes the slewing bearing 105, and is capable of slewing the upperframe 104 360 degrees with respect to the lower frame 103. As a result,the work range can be widened, and the work efficiency can be improved.

Moreover, according to the present embodiment, the lower frame 103includes the link frame 103A, the support plate 103B, and the connectionpart 103C. The link frame 103A connects the pair of track frames 101 ato each other. The support plate 103E supports the slewing apparatusincluding the slewing bearing 105. The connection part 1030 connects thesupport plate 103B to the link frame 103A. The connection part 1030includes the tilting apparatus 106 for lifting a front part of thesupport plate 103B and tilting the upper frame 104. As a result, theheight of the bucket at the time of upward movement. for dumping can bemade higher, and hence the work range can be widened.

Moreover, according to the present embodiment, because the tiltingapparatus 106 includes the tilt cylinders 106 b made of hydrauliccylinders, the operation stability and the quietness can be improved.

Moreover, according to the present embodiment, the loader work apparatusincludes: the pair of right and left booms 107 (107A) supported by thebase frame 102; the bucket 108 provided to the leading ends of the pairof booms 107 (107A) ; and the boom cylinders 112 (112A) capable ofswinging the pair of booms 107 (107A) in the top-bottom direction. Theloader work apparatus further includes the moving apparatus capable ofmoving the pair of booms 107 (107A) forward. As a result, a work toolthat may be unfavorably located backward in the case of moving the boomupward can be shifted forward, and the work efficiency using the worktool can be improved.

Moreover, according to the present embodiment, the moving apparatusincludes: the moving cylinders 114 that are supported by the base frame102 and are each made of the hydraulic cylinder; and the moving links116 that are turnably supported by the base frame 102 and each have oneend connected to each of the moving cylinders 114 and another endconnected to each of the pair of booms 107 (107A). The boom cylinders112 (112A) are supported by the base frame 102. The pair of booms 107(107A) are made movable forward by respectively driving the moving links116 by the moving cylinders 114 in the state where the pair of booms 107(107A) are respectively supported by the boom cylinders 112 (112A). As aresult, the apparatus can be downsized.

Note that actions and effects described in the embodiment of the presentinvention are merely the most preferred actions and effects producedfrom the present invention, and actions and effects produced from thepresent invention are not limited to those described in the embodimentof the present invention.

-   100 track loader (loader work machine)-   101 traveling apparatus-   101 a track frame-   102 base frame-   103 lower frame-   103A link frame (link frame part)-   103B support plate (support part)-   103C connection part-   104 upper frame-   104A cabin-   105 slewing bearing-   106 tilting apparatus-   106 b tilt cylinder-   107 boom-   107A boom-   108 bucket (work tool)-   112 boom cylinder (swinging apparatus)-   114 moving cylinder (movement cylinder)-   116 moving link (link member)-   201 a track frame-   201 b sprocket (drive wheel)-   201 c front idler-   201 d rear idler-   201 e track roller-   201 f rubber track-   FIG. 1-   #1 TOP-   #2 BACK-   #3 BOTTOM-   #4 FRONT-   FIG. 2-   #1 TOP-   #2 RIGHT-   #3 BOTTOM-   #4 LEFT-   FIG. 3-   #1 TOP-   #2 BACK-   #3 BOTTOM-   #4 FRONT-   FIG. 5-   #1 TOP-   #2 BACK-   #3 BOTTOM-   #4 FRONT-   FIG. 6-   #1 TOP-   #2 BACK-   #3 BOTTOM-   #4 FRONT

What is claimed is:
 1. A loader work machine comprising a base frameincluding a cabin; a loader work apparatus attached to the base frame;and a pair of traveling apparatuses that support the base frame, whereinthe traveling apparatuses each include: a track frame connected to thebase frame; a drive wheel that rotationally drives a traveling belt; afront idler and a rear idler that are arranged in a front--backdirection below the drive wheel and are rotatably supported by the trackframe; and one or more track rollers that are arranged between the frontidler and the rear idler and are rotatably supported by the track frame,the traveling belt being stretched around the drive wheel, the frontidler, the rear idler, and the track rollers, the base frame includes: alower frame that is connected to a pair of the track frames and isinterposed between the pair of traveling apparatuses; an upper framethat is provided with the loader work apparatus and is arranged abovethe lower frame; and a stewing apparatus that slewably connects theupper frame to the lower frame, and the upper frame is connected to thelower frame at a position at which a bottom surface of the upper frameis above the traveling belts.
 2. The loader work machine according toclaim 1, wherein the slewing apparatus includes a slewing bearing, andis capable of slewing the upper frame 360 degrees with respect to thelower frame.
 3. The loader work machine according to claim 1, whereinthe loader work apparatus includes a pair of right and left boomssupported by the base frame; a work tool provided to leading ends of thepair of booms; and a swinging apparatus capable of swinging the pair ofbooms in a top-bottom direction, and the loader work apparatus furtherincludes a moving apparatus capable of moving the pair of booms forward,4. The loader work machine according to claim 3, wherein the movingapparatus includes movement cylinders that are supported by the baseframe and are each made of a hydraulic cylinder; and link members thatare turnably supported by the base frame and each have one end connectedto each of the movement cylinders and another end connected to each ofthe pair of booms, the swinging apparatus includes boom cylinders thatare supported by the base frame and are each made of a hydrauliccylinder, and the pair of booms are made movable forward by respectivelydriving the link members by the movement cylinders in a state where thepair of booms are respectively supported by the boom cylinders,